1. Field of the Invention
The present invention relates to a far-infrared (FIR) material that emits in a narrow wavelength region and is used as the radiation emitter in therapeutic tools. This FIR material emits strongly and exclusively in the 9 to 12 micron wavelength range. It is used passively as a heating pad when the heat from the body stimulates the FIR emission. It is used as an active emitter when it is the hot element of a therapeutic device such as a heat massager.
2. Technical Background
In the last two decades Japanese scientists and physicians have discovered that far infrared (FIR) waves have therapeutic and sanitary effects. Many Japanese patents have been filed in Japan covering FIR technology. Some patents have been applied for in the U.S. Generally, they describe a particular ceramic that emits FIR waves or a process to coat FIR ceramics onto heating elements.
Near infrared waves are waves with wavelengths between 0.8 and 3 microns. FIR waves are long wavelength radiation with a wavelength longer than 3 microns. Usual FIR emitting materials are the ceramic oxides. They include magnesium oxide, aluminuma silicates, quartz (silicon dioxide), iron oxide, aluminum oxide, zirconium oxide, and titanium dioxide. While these materials are good FIR emitters, the radiation emitted is generally broad, covering typically 3 to 15 microns.
Major uses for far-infrared rays are in therapeutics and in sanitation. Patents found that are related to therapeutics are listed in references 1, 2 and 3. The patent related to sanitation is reference 4. Reference 1 describes fibers that are made from far-infrared emitting materials and are made into in clothing. Reference 2 describes a powder and fibers made from the powder that have high far-infrared emissivity. The powders and fibers are made into therapeutic clothing and sanitary wraps. Reference 3 describes a far-infrared lamp that emits strongly in the 8 to 9 micron region. The radiation in this region is claimed to be highly therapeutic. Reference 4 describes an apparatus that sterilizes articles placed inside through bombardment with far-infrared radiation.
The human body emits strongly in the 8 to 13 micron range, peaking at 10 to 11 microns. DNA has been found to have strong absorption at 11 microns. Therapeutic effects and sanitation effects are also strongest in this region. Therefore, the most efficient FIR material for use in therapeutics and sanitation would emit strongly in the 8 to 13 micron region and little elsewhere. However, prior art does not cover efficiently this wavelength region. References 1 and 2 describe inventions that emit broad band FIR radiation. Reference 3 describes a narrow band FIR device (8 to 9 microns) of rather complicated construction. For these reasons a search was conducted to find a more suitable FIR material. The material must meet two main criteria: (1) Strongly emits in the 8 to 13 micron region and little elsewhere. (2) Formable so as to be easily formed into therapeutic tools.
A search was conducted to find a material that meets the requirements of emission characteristics (8 to 13 microns) and formability. The search was conducted both experimentally and through the literature. Experimentally, different materials were examined using a FTIR (Fourier Transform Infra-Red) spectrometer. Literature wise, published far-infrared spectra were collected from various library sources. This search has found a material that exclusively and strongly emits (and hence also absorbs) radiation in the 9 to 12 micron band. This material is almost transparent to infrared waves below 9 microns and above 12 microns in wavelength. The material is polyvinylfluoride (PVF). FIG. 1 shows a schematic of its emission characteristics. The oxide materials mentioned above generally do not have such specific emission characteristics.
This document discloses the application of a FIR material for two therapeutic tools. The first tool is that of a passive heating pad. The FIR material, in sheet form, is first coated with silver, through a process such as vacuum sputtering. The silver provides two functions: First as a surface of low emissivity so that the emissions from the FIR material dominates. Second, the silver reflects back heat to prevent heat loses. The silvered side is then laminated to a rubber sheet substrate to provide support. The FIR sheet is about 1.5 mil thick and the rubber substrate is about 10 mil thick. These thicknesses can be varied. This heating pad is shown in FIG. 2. A large pad is used as a mattress pad. A medium pad is used as a local body pad. A small pad is used as an insole for shoes.
The prototype pad was tried as a mattress pad and as a shoe insole. The prototype mattress pad gave an immediate comfortable warm feeling. It is a pleasant warmth and not a hot feeling. The amount of sleep was reduced immediately. Overall, an improvement in well-being was noted.
To explain the function of comfort due to a feeling of increased warmth, it is noted that body temperature varies very little from 98.6 degrees F. or about 38 degrees C. At this temperature the body IR emission peaks at about 10 to 11 microns. Hence IR rays of this wavelength are comfortable to the body. An increase in the 10 to 11 micron radiation, as provided by the FIR sheet, without radiation outside the 9 to 12 micron window, provides a xe2x80x9ccoolxe2x80x9d warmth. By xe2x80x9ccoolxe2x80x9d we mean a feeling of warmth and comfort without a great deal of heating of the body as would be the situation with most emitting surfaces. The heat from the FIR material is selectively absorbed in the DNA and in breaking up water clusters. With most other emitting surfaces the broad band radiation mostly goes to heating up the body. The body is mostly water and broad band IR radiation will heat up water. On the other hand, the DNA absorption and breaking up of water clusters are useful functions that don""t contribute directly to heating up the body. All these reasons contribute to the comfortable xe2x80x9ccoolxe2x80x9d heat provided by FIR material.
One explanation of the feeling of well-being lies with cellular absorption and elimination. The water that we drink comes in clusters of water molecules. The clusters can range from one molecule to dozens of molecules. The clusters are broken up most efficiently in the far infrared ranges. Water cluster size is important in cellular activity. The smaller clusters, working in groups, are able to wrap around ions and transport them. The larger clusters have more difficulty in trapping ions. An additional reason for difficult transport is the size which makes intermembrane transport easier for smaller clusters and smaller cluster/ion units and difficult for large clusters. Thus, intermembrane transport, which is important in cellular absorption and elimination, is enhanced with smaller water clusters.
A second application is the use of the FIR material as the hot emitting element in a heat/cold massager. It is also the cold absorbing element in the heat/cold massager. This heat/cold massager consists of a Peltier junction thermoelectric heat pump. The heat pump consists of two aluminum plates separated by a series of Peltier junctions. With power on, one aluminum plate will be hot and the other plate will be cold. A heat/cold massager unit is made by laminating the FIR material, in sheet form, to both aluminum plates. FIG. 3 shows a schematic of this device. Thus, the hot side is used to provide FIR heat to a part of the body. The other side is to provide xe2x80x9ccoldxe2x80x9d, that is, it acts as a heat sink by absorbing 9 to 12 micron radiation. The hot and cold plates do not touch the body but perform their operation at a distance through FIR radiation. One method to prevent touching is through the use of FIR transparent covers over the plates.
The prototype unit provides a heating effect similar to the heating pad but at a higher level to a smaller area. The cold operation also gave a comfortable feeling. Headaches and inflammations, such as burning eyes, are helped with the cold operation.
Another important FIR function is in sanitation. Japanese scientists have shown that bacteria growth is slowed and stopped by FIR radiation. How this mechanism works is uncertain at present (reference 4). The FIR pad and the FIR massager as described in this document are also presumed to work against bacteria growth.
We have disclosed a FIR material and its application in two devices. The first device is a heating pad. The second device is a heat/cold massager. Both the pad and massager give a feeling of warmth and comfort and improves cellular health. Thus, the overall well-being and health of the user is improved with this invention. An additional benefit is the sanitation effect of reduced bacterial activity.